Delivering preheated air to combustion chambers



Nov. 17, 1931. G. VAN DAAM DELIVERING PREHEATED AIR TO COMBUSTION CHAMBERS Filed Dec. 2-7. 1929 Patented Nov. 17, 1931 UNITED STATES GERRIT VAN DAAM, OF BUFFALO, NEW YORK DELIVERING PREHEATED' AIRIO COMBUSTION CHAMBERS Application filed December 27, 1929. Serial No. 416,828 I My invention relates to delivering preheated air to combustion chambers, and is especially applicable to the combustion of coal, where the unburned gases rise from the fuel bed and are mixed with the preheated air delivered thereto to facilitate the combustion of said gases.

The invention is especially directed to the method and means for controlling the flow of air through oppositely directed paths of travel within the heat zone of the combustion chamber in order to secure maximum efficiency of heat transfer to said incoming air.

The invention comprises improvements in the invention disclosed in my Patent No.

1,717,421 dated June 18,1929.

Referring to the drawings which illustrate merely by way of example, suitable .means for effecting the invention Fig. 1 is a central longitudinal section of the air heating element.

Fig. 2 is a cross-section on the line 2, 2 of Fig. 1.

Fig. 3 is an elevation of the intake end.

Fig. 4 is an elevation of the discharge end.

Similar numerals refer to similar parts throughout the several views.

A chambered formation 6 is preferably formed of double substantially parallel corrugated walls 7 and 8 provided with integral spacing elements 9 and forming between said walls an undulating air passage 10 from one end to the other of said chambered formation. A space or chamber 11 is also provided within the wall 8 of corresponding extension. Within this chamber 11 is provided a tubular formation 12 tapering from the inlet ,end to the discharge end, and also with a flaring mouth 13 at the inlet end of said tubular formation.

A disc 14 provided with an annular flange 15 having an exterior and an interior thread as shown in Fig. 1, is threaded into the annular flange 16 of wall 7 of the chambered body and is threaded onto the flaring end 17 of the tubular formation 12 and supports the said tubular formation centrally with respect to the chamber or space 11. A centrally disposed threaded aperture is also provided on disc 14 into-which is secured the pipe 18 extending through the wall'or door of the combustion chamber and onto which is threaded the chambered formation or head 19 which is positioned outside the 56 combustion chamberand serves as a clamp to secure the parts in place. This formation 19 is provided with air intake openings 20 delivering to; space 21 of said formation, which space is in communication, through pipe 18 with the tubular formation 12. This delivery may be controlled by any suitable thermostatically operated valve such as 22.

- At the other end of the chambered formation 6 is provided a disc 23 having a centrally 85 extending lug 24 threaded into the end of wall 8 of said chambered formation. The outer margin of disc 23 is provided with a beveled edge 25to form an airtight engagement with a correspondingly beveled seat 26 formed on the end of wall 7 of said chambered formation. This disc 23 is provided with a number of discharge vents 27 for delivering the preheated air from the passage 10 to the combustion chamber. 7

t It is also to be noted that a space 28 is provided between the end 29 of wall Sand the tubularformation 12, for the passage of from passage 10 to chamber 11. I

In operation, the chambered formation 6 is supported within the heat zone of the combustion chamber and securedor clamped in place against the wall or door of the combustion chamber by means of thetube-or'pipe 18 and the head 19 as described. 3

The airentering through the ports 20 passes through the pipe 18 to the tubular formation 12 discharging through the small end thereof into the chamber 11, thence pass-. ing in the opposite direction the entire length of said chambered body 6 to the space 28 through which it passes to and through passage 10, in direction opposite to that through chamber 11, to and through the discharge vents 27 into the combustion chamber. The movement of the air from port 20 to and through vents 27 is efiected by the natural draft of the furnace. The normal velocity of the air travel is however modified by the air expanding of the air, as its temperature rises and by the contracting form of the passage through the tapered tubular formation 12 in one direction, and of the chamber 11 surrounding the formation 12, in the opposite direction; that is to say, the velocity of air travel is modified by the factors of air expansion and retardation due to the contraction of the cross-sectional areas of the passages within and surrounding formation 12; thus the air in its forward, then backward and then again forward movement in the chambered formation 6, has ample time to become thoroughly heatedbefore delivering to the combustion chamber.

15 What I claim is 1. In a device of the character described, a chambered formation adapted to be supported within the heat zone of a combustion chamber, said formation comprising double undu- 29 lating substantially parallel walls providing a channel therebetween, a disc secured to one end of said formation having clamping means for supporting said formation and air intake means, a disc secured to the other end 5 of said formation having air discharge vents,

and a tubular formation secured to the intake disc and centrally disposed within said undulating walls and tapering from its intake to its discharge, and forming with said undulating walls reversely directed passages of gradually decreasing cross-section.

2. In a device for delivering preheated air, the combination of a formation adapted to be supported within the heat zone of a combustion chamber, said formation comprising double i undulating substantially parallel walls secured together in spaced relationship and providing a longitudinally extending air passage therebetween, means at one end of 49 said formation providing a support therefor and also an air intake thereto, means at the other end providing air discharge vents from said passage, and a longitudinally extending centrally located tube within the formation supportedat the intake end and in communication with said-intake, said tube tapering from the intake toward the discharge and forming, with the inner undulating wall, reversely' directed passages of decreasing cross-section.

GERRIT VAN D 

